Automatic analogue breathing system for multicell pressure suits



United States Patent [72] Inventor Otto Schueller Dayton, Ohio [21] Appl. No. 729,333 [22] Filed May 15, 1968 [45] Patented Sept. 15, 1970 [73] Assignee The United States of America as represented by the Secretary of the Air Force [54] AUTOMATIC ANALOGUE BREATHING SYSTEM FOR MULTICELL PRESSURE SUITS 10 Claims, 7 Drawing Figs.

[52] US. Cl 128/1425, 2/2.l, 128/146 [51] Int. Cl. A62b 7/00 [50] Field of Search 128/28, 30, 30.2,142,142.5,142.6;2/2.1; 128/1.1, 146

[56] References Cited UNITED STATES PATENTS 1,226,148 5/1917 Walters 128/1425 3,077,881 2/1963 Sprague 128/1425 3,457,918 7/1969 Dibelius et a1 Primary Examiner-Adele M. Eager Attorneys-Harry A. Herbert, Jr. and Charles H. Wagner ABSTRACT: An automatic breathing system and apparatus for multicell pressure suits which compensates for pressure changes in an expandable pressure medium in the cells of the suit during breathing and balances the expansion and compression forces of the lungs and cells during the entire breathing cycle and compensates for volume deviations of different individuals in the same size range of standardized multicell pressure suits which apply mechanical pressure to the skin by the expansion of air sealed in a multitude of expandable and collapsible cells or tubes between the body of the wearer and an outer restraint garment, operating upon the Boyles Law principle. Means are provided in the suit which automatically vary the breathing pressure supplied to the wearer to substantially balance any increase or decrease in the expansion or reduction of pressure of the cells on the body of the wearer during the breathing cycle, especially in the thorax area.

Patented set.15,1970 3,528,414

.Sheet 1 of '7 v INVENTOR 07'7'0 SCI/(I614 [4 BY Z ATTORNEY Patented Sept. 15, 1970 3,528,414

Sheet 2 of 7 INVENTOR 077 0 SCf/Ufllfl? Patented Sept. 15, 1970 3,528,414

Sheet 4 INVENTOR arr-o 5010a; 5e

7 Z 1 W A ORNEY Patented Sept. 15, 1970 3,528,414

Sheet 5 of7 INVENTOR 0 7'70 36'! 4 a a? A ORNEY Patented Sept. 15, 1970 3,528,414

Sheet 6 of? ATTORNEY AUTOMATIC ANALOGUE BREATHING SYSTEM FOR MULTICELL PRESSURE SUITS CROSS REFERENCES TO RELATED APPLICATIONS This invention relates to improvements in the Boyles Law types of high altitude pressure suits, such as shown and described in the US. Pat. application to Otto Schueller for Multicell Pressure Suit, filed 3 June 1965, Ser. No. 461,212, now US. Pat. No. 3,428,960 and US Pat. application to F. R. Ritzinger et al., for Emergency Altitude Pressure Suit (Boyles Law Operated), filed May I967, Ser. No. 639,930

BACKGROUND OF THE INVENTION The principle of the multicell pressure suit consists of the application of mechanical pressure to the skin or outer surface of a wearer of the suit by the automatic expansion of air sealed in a multitude of collapsible cells or tubes between the wearers body and an outer somewhat porous restraint garment when the exterior or atmospheric pressure surrounding the suit is reduced. According to Boyles Law, the gas or air trapped and sealed in the cells expands as the air pressure outside of the cells is reduced. This expansion of the gas cells, restricted by the nonextensible outer garment, presses inwardly against the body of the wearer as the surrounding pressure decreases, for instance, with increases in altitude.

Of course, as the altitude decreases the atmospheric pressure increases which causes a corresponding compression of the gas-containing collapsible cells, and a corresponding reduction or relief of pressure on the outer surface or skin of the wearer, even to the extent that the suit may become loose and very comfortable on the ground and at lower altitudes, or in pressurized cabins or stations but becomes instantly and automatically operable should decompression in a pressurized cabin occur, or upon increases in high altitudes where a full or partial pressure suit would ordinarily be necessary.

In prior multicell pressure suits, it was found that the expansion and reduction in volume of air in the thorax area of the wearer due to inhalation and exhalation breathing changes the inner volume of the suit, especially in the thorax area. The wearer has to exert compression work on the air in the cells when breathing in the oxygen or oxygen mixture at high altitudes, while using a conventional oxygen or oxygen demand regulator. This breathing against expanded cell pressure on the thorax area of the wearer, however, was extremely difficult. For instance, a pressure difference during inhalation of 10mm Hg required to expand the thorax area of the wearer means a load of about 28 pounds per square foot on this thorax area. While this can be relieved to some extent by making the trapped air or gas cells much larger so as to provide a greater space between the exterior garment and the skin of the wearer which is occupied by the expansible cells or sealed air chamber material, it causes the suit to be much heavier and clumsy, but the objection caused by this breathing fatigue would not be entirely eliminated.

The improved breathing system of this invention entirely, or substantially entirely, eliminates the fatigue of the breathing effort in the multicell and similar pressure suits by utilizing the energy stored in the compressed oxygen used and supplied to the wearer for doing the necessary compression work on the air in the closed cells of the suit during the inhalation cycle. This relieves the wearer from the fatigue of breathing against the expanded cells, especially over the thorax area, and also permits a considerable reduction in the cell volumes, and reduction in the bulk or thickness of the suit.

An object of the invention therefore is means for pressure suits of the Boyles Law operated types which relieves breathing fatigue of the wearer due to changes in the volume of the interior of the suit caused by exhalation and inhalation breathing by the wearer.

A further object is the provision of a pressure sensing means which is located in the thorax area of the suit for regulating the inhalation breathing pressure supplied to the wearer to substantially balance the trapped and sealed in air or gaseous pressure in the cells located especially in the thorax area, during breathing inhalation and exhalation by the wearer.

A further object is that of utilizing the energy stored in the compressed oxygen which is supplied to the wearer at a predetermined pressure for breathing to do the necessary compression work on the air in the closed cells of the suit to substantially balance the expansive pressure of the cells on the wearers thorax area to relieve fatigue breathing by the wearer while the exterior pressure surrounding the suit and cells is materially reduced or eliminated.

Other objects and advantages of the invention will become apparent from the following description and accompanying drawings in which like reference characters refer to like parts in the several figures.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary schematic sagital sectional view through the thorax area of a multicell pressure suit having the invention incorporated therein, with an oxygen demand regulator used therewith, shown in considerably enlarged relation and in forwardly spaced relation to the front of thesuit, for diagrammatic purposes. In actual practice, this oxygen demand regulator may be relatively much smaller and disposed in any convenient location and connected to the pressure sensor in the suit and to the breathing mask or breathing helmet by suitable flexible communicating conduits. This figure of the drawing shows the operation of the apparatus during the inspiration" or inhalation phase of the breathing cycle. FIG. 2 is a view similar to FIG. 1 but showing the operation of the device during the expiration" or exhalation phase of the breathing cycle.

FIG. 3 is an enlarged sectional view of a slightly modified oxygen demand breathing pressure supply regulator, with the pressure sensor which is normally disposed in the thorax area of the multicell pressure suit shown somewhat schematically, and by itself. The parts are shown in their expiration or exhalation phase positions. This view shows manual means for the adjustment of the regulator to suit the individual comfort requirements and functions for supplying oxygen on demand for breathing, together with means for regulating the rate of flow of oxygen into the regulator device.

FIG. 4 is a modified view, somewhat similar to FIGS. 1 and 2, but showing the demand oxygen regulator mounted on the exterior or front of the multicell pressure suit over the thorax area and connected directly to the pressure sensor, showing the position of parts therein during the inspiration or inhalation phase.

FIG. 5 is a view similar to FIG. 4 but with the parts moved to the expiration phase position. I

FIG. 6 is a somewhat schematic, fragmentary sectional view, showing the outer porous restraint garment and the spaced inner porous liner with the sealed air or gas-filled collapsible and expansible cells therebetween, showing the cells partially expanded to occupy the space between the outer porous restraint garment and the porous expandable or stretchable inner liner, next to the skin or outer surface of the wearer.

FIG. 7 is a sectional view of a further modification of an oxygen demand regulator, somewhat similar to the oxygen demand pressure regulator shown in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, the reference numeral 1 generally denotes a Boyles Law", high altitude, pressure suit; however, only the upper portion thereof is shown.

The suit 1 comprises an outer, porous, nonextensible, restraint garment 2 with an inwardly spaced porous inner garment or liner 3, which is expandable, contractable, comfortable and flexible, and is adapted to lie next to the wearers skin, or his skin covering garment.

Interposed between the outer restraint porous layer 2 of the suit 1 and the spaced inner porous layer or liner 3 are a plurality of collapsible and expandable air or gas containing sealed cells or tubes 4.

These cells 4 are hereafter also referred to as the multicells of the suit. These multicell structures may be in the form of small expansible and collapsible tubular chambers, with predetermined amounts of air or gas sealed therein as shown in the drawings, as well as sponge-like rubber strips or pads with air or gas trapped and sealed in the cells thereof, preferably at less than the normal atmospheric pressure at ground or sea level. In other words, the cells 4 each have a predetermined amount of air or gas trapped and sealed therein so that the cells are normally partially collapsed as shown in the drawings or not under expansive pressure at low altitude conditions so as not to fully or tightly occupy the space between the inner and outer garments 3 and 2 at altitudes where or when a pressure suit is necessary. The gas or air expands in the cells according to Boyles Law with increases in altitude and corresponding reductions of the outside cell surrounding pressures.

Beginning at predetermined altitudes where oxygen breathing becomes necessary, the cells automatically expand sufficiently by the expanding air or gas trapped therein, as shown in the drawings, to automatically exert the necessary increasing pressure on the outer surface of the wearer.

Reduction in altitude in the Boyles Law type of suits increases the exterior atmospheric pressure on the cells causing them to automatically decrease in size and reduce or eliminate the inward expansion pressure thereof on the outer surface or skin of the wearer. This automatically makes the suit comfortable to wear at lower altitudes over long periods of time and there is little or no danger of puncture with a corresponding complete decompression or loss of air, as would be the case with a puncture in the conventional inflatable full pressure suits.

In the drawings the reference numeral 5 denotes an oxygen supply helmet having a transparent and sealed front panel or visor 6 with a neck seal 7 to confine the supply of breathing oxygen from the oxygen demand and control regulator, indicated generally at 10, into the helmet 5 above the neck seal 7.

For purposes of illustration, an oxygen demand supply regulator 10, modified according to the invention, has been schematically shown on a relatively greatly enlarged scale. This regulator can be made very small and may be mounted out of the way on the suit, or even in or on the helmet instead of in front of the wearer as shown in FIGS. 1 and 2.

As previously mentioned inhalation becomes difficult in the previous Boyles Law types of suits as contemplated in the previously referred to Schueller and Ritzinger, Jr. et al. patent applications because when the cells expand, especially in the thorax area, these cells have to be compressed again by the expansion of the wearer's lungs. On the other hand, where the lung pressure is balanced against the expanding and contracting cell pressure on the thorax area, this breathing can be made easy and natural with substantially no effort or fatigue on the part of the wearer of the suit. The subject invention accomplishes this by providing a relatively small collapsible and expandable pressure sensor 9 in the thorax or chest area of the suit 1, between the inner porous layer 3 of the garment and the outer nonextensible porous layer 2. This pressure sensor 9 is connected to automatically control the pressure of the oxygen supplied into the helmet 5 for breathing to balance the external pressure on the chest area of the wearer, supplied from an oxygen demand regulator indicated generally at 10, and schematically shown on an enlarged scale in FIGS. 1 and 2 in spaced relation to, and in front of the suit, or mounted directly on the exterior of the suit in front, over the thorax area, and connected directly to a pressure sensor 9, as shown schematically in FIGS. 4 and 5.

The oxygen demand regulator 10 comprises a casing 11 with a central partition 12 dividing the casing 11 into an oxygen intake chamber 13 and an oxygen outlet chamber 14. The oxygen inlet chamber 13 is supplied with oxygen (or oxygen mixture) from a higher regulated pressure oxygen source (not shown) through a valve controlled inlet port and conduit 15 while the oxygen outlet chamber 14 is connected by a suitable oxygen delivery conduit or hose 16 to the interior of the suit wearers mask or helmet 5.

A flapper type disk inlet valve 17 is provided in the hel ment 5 opening inwardly under pressure, but preventing exhalation pressure from the breather from entering the conduit 16. The helmet 5 is provided with the exhalation port 18 which is also controlled by a disk type flapper outlet valve 19 that is urged to closed position during the inhalation cycle by an actuating diaphragm 20. The diaphragm 20 is disposed across a chamber 21, with a small oxygen pressure supply conduit 22 from the chamber 21 connected in communication with the oxygen supply conduit 16.

Inhalation and corresponding expansion of the chest or thorax area of the wearer opens the oxygen inhalation or breathing valve 17 and the outlet or exhalation valve 19 closes, assisted by the inlet pressure in the pipe or conduit 16 on the diaphragm 20, supplied through the small or bypass pressure supply conduit 22.

Exhalation, of course, closes the inhalation or inlet valve 17 and opens the exhalation or outlet valve 19 and the chest or thorax area of the wearer in the suit contracts, permitting the multicells 4 in the chest area to expand, including the air or gas contained in the pressure sensor cell or chamber 9.

As shown in FIGS. 1 and 2, the casing of the oxygen demand regulator 10 is closed at both ends by the flexible diaphragms 23 and 24, which are spaced from the central wall or partition 12. The diaphragm 23 closes the outer (left) end of the oxygen inlet chamber 13 while the diaphragm 24 closes the outer end of the oxygen outlet chamber 14.

The oxygen demand regulator casing 10 has a first bell or cup shaped extension 25 with the interior thereof open to atmosphere, in which is located an oxygen supply valve actuating bellows 26, while a similar cup shaped enclosure 27, open to atmosphere, extends outwardly from the outer end of the oxygen outlet chamber 14 and encloses a second or oxygen demand valve actuating bellows 28 for controlling the oxygen demand valve 29, shown in open position in FIG. 1, and closed in FIG. 2. The oxygen demand valve 29 is moved between open and closed positions by a lever 30 pivoted at its lower end, as shown, to the casing 11 and at its opposite end to the center of the diaphragm 24, with the lever 30 having an intermediate connection or pivot to the stern of the oxygen demand valve 29. A light spring 31 presses the valve 29 toward its closed position as shown in FIG. 2. The oxygen pressure control valve 32 for the oxygen inlet port 15 is connected by a bell crank lever 33 fulcrumed on the casing 11, and a link 34 to the other diaphragm 23 with a light spring 35 between the link 34 and its connection to the bell crank lever 33 provided to urge the valve 32 toward its closing position.

The bellows 26 and 28 are fixed at their centers to the centers of the outer ends of the cup shaped casings 25 and 27, with their exteriors exposed to atmosphere through the ports 26a and 280 respectively in the sides of the cup shaped extensions 25 and 27, and the bellows are connected in communication with the interior of the pressure sensor 9 through the conduit 36 and the branch conduits 36a and 36b leading therefrom to the interior of the bellows 26 and 28 respectively.

Referring to FIG. 3, the same parts shown therein as shown in FIGS. 1 and 2 have been given the same reference numerals.

The levers 37 and 38' are adjustable by the wearer, through the threaded connections 37a and 38a to move the mounting plates 37b and 38b selectively in or out to regulate the pressure of the bellows members 26 and 28 against the diaphragms 23 and 24.

A control valve 39 is adjustable to bypass a regulated or controlled flow of oxygen into the conduit 16 for emergency oxygen supply.

FIG. 3 illustrates an automatic breathing system with a modified conventional oxygen demand regulator to provide manual adjustments of the breathing pressure to suit individual comfort requirements. The effective volumes of the bellows 26 and 28 can be varied by the hand actuators 37' and 38', and as shown schematically, the pressure sensor 9 is removed from the suit.

FIG. 3 also shows known means for automatically interrupting the oxygen supply from the chamber 14 and admitting outside atmospheric air for breathing through the valve 42 when the outside air pressure materially exceeds the pressure in the demand pressure supply chamber 14, and. includes means operable by differential pressure between the interior and exterior of an aneroid such as 40, with camming means 41 for manually controlling the oxygen supply and the outside atmospheric air that is supplied to the wearer of the suit through the conduit 16.

In cases of temperature increase during an emergency, for example by aerodynamic heating of the cabin, or other reasons, the gas temperatures in the cells 4 of the suit would increase. With a corresponding increase in the gas cell pressures, breathing would ordinarily be impaired. The demand regulator with the pressure sensor cell 9 as shown would automatically increase the breathing pressure to consistently maintain the balance between suit and breathing pressures.

FIGS. 4 and 5 show a simplified version of the automatic pressure breathing system. The demand regulator 10' is built into the suit and the aneroid 9, somewhat similar to the bellows 26, is directly used as the pressure sensor instead of the separate pressure sensor 9. The oxygen inlet pressure control valve 32 is actuated directly by the mechanical movement of the chest or thorax area of the wearer, while the oxygen demand valve 29 is controlled by the pressure changes on the diaphragm 24 during breathing.

During inspiration the diaphragm 24' moves inwardly and the demand valve 29' is opened. During expiration the pressure on the diaphragm 24 momentarily rises and diaphragm 24' moves outwardly and the oxygen demand valve 29' is closed.

Of course, the aneroid 9' has a predetermined quantity of air or gas trapped and sealed therein and moves bodily in and out against the diaphragm 23 during breathing and actuates the diaphragm 23. The pressure sensor 9' is exposed to atmosphere through the ventilation pores of the suit and will expand or contract, according to Boyles Law.

If the exterior (atmospheric) pressure is sufficient, the aneroid 9' will be contracted sufficiently to close the valve 32. The helmet visor 6' can then be opened, or helmet 5' removed or the oxygen outlet chamber 14' may be provided with a spring closed fresh air inlet port and valve indicated at 14' which can be opened by suction (inhalation) upon a predetermined increase in the outside atmospheric air pressure when the oxygen supply valve 32' is closed, because of collapse of the pressure aneroid" sensor 9' at low altitudes (where oxygen is not required).

Referring to FIG. 6, the pressure force F, of the internal lung pressure P is:

,F;,=Area ABXPL The pressure force F of the cell gas pressure P is:

F =area ACXPC To keep these pressure forces in balance, the ratios of the effective cross section of the bellows 26 and 28 to the cross section of the diaphragms 23 and 24 must be equal to the body area covered by the cells, to the total body surface area. In other words, the bellows and diaphragms are analogue models on a reduced scale of the cells of the suit and the thorax, respectively.

FIG. 7 is a sectional view showing a modified oxygen demand regulator 10a, somewhat like the regulator 10, and similar parts to those shown in the other FIGS. are denoted by similar reference numerals.

, through conduit 13c.

The bellows 13b, when expanded by the regulated oxygen supply pressure in conduit 15', operates to urge the oxygen inlet valve 32 toward closed position as seen in FIG. 7.

A safety valve 38 is provided in the oxygen inlet chambers of the modified demand regulators as shown to limit an excessive pressure build-up in the inlet chambers of the demand regulators shown in FIGS. 1, 2, 3 and 7, and may be provided in the regulator shown in FIGS. 4 and 5, if desired.

Briefly describing the operation of the system and invention, assuming that the wearer has donned the suit 1 and helmet 5, the exterior of the suit is being subjected to a decreasing atmospheric pressure, or complete lack of exterior atmospheric pressure, where oxygen must be supplied for breathing.

The suit being porous, in additon to providing ventilation, any reduction in exterior pressure on the sealed expandable tubes or multicells 4 causes expansion of the amount of air or gas sealed in the cells or tubes to expand, according to Boyles Law.

Since the outer layer or fabric of the suit is not only porous, but is nonexpansible or extensible, the expanding cells or tubes 4 force the inner loose or expansible liner 3 of the suit into pressure supporting engagement against the skin or the outer surface of the wearer.

The expanding air or gas trapped and sealed in the pressure sensor 9 and in the connected pipes or conduits 36, 36a and 36b, and the bellows 26 and 28, forces the bottom end of the expansible pressure sensor 9 against the surface of the thorax area of the wearer, as shown in FIG. 1 and supports or helps to support the contacted area occupied by the pressure sensor 9.

During the exhalation or expiration phase, the air in the wearers lungs is discharged through the outlet 18 in the helmet 5. The diaphragm 24 in the pressure demand regulator 10 moves outwardly (to the left) to close the oxygen demand valve 29 because the increase in the volume and reduction in the pressure sensor 9 reduces the pressure in the bellows 28 (and also in bellows 26) allowing the pressure in the chambers 14 and 13 to move the diaphragms 24 and 23 in directions away from the partition 12. This moves the oxygen demand valve 29 toward closed position and the oxygen inlet or supply valve 32 toward its closed position as seen in FIG. 2. This closes off or tends to close off the oxygen supply conduit from the pressure regulated oxygen supply source (not shown);

In this system and apparatus the internal lung pressure of the wearer always balances, or is only slightly greater than the unit pressure of the cells 4 on the outer surface of the skin of the wearer, particularly on the thorax area, making exhalation easy and comfortable.

During inhalation or inspiration, the change in the positions of the parts as shown in FIG. 2 to those shown in FIG. 1 causes the exhalation valve 19 to close and the inhalation valve or diaphragm 17 to open. The expansion of the thorax area of the wearer forces some of the air or gas from the interior of the pressure sensor 9, through the conduits 36, 36a and 3612 into the two bellows 26 and 28. The expansion of these bellows move or tend to move the two diaphragms 23 and 24 in directions toward the central partition 12. This movement of the diaphragm 24 opens the oxygen demand valve 29, while this movement of the other diaphragm 23 opens the regulated pressure oxygen supply valve 32, allowing oxygen from the chambers 13 and 14 to be supplied under predetermined pressure through the conduit 16 and valve 17 into the helmet 5, and into the lungs of the wearer.

This pressure, controlled by the oxygen demand valve 29 and oxygen supply valve 32, is supplied to the lungs of the wearer with sufficient pressure to progressively balance the increasing pressure of the multicells 4 on the thorax area of the wearer as the cells 4 in the thorax area are compressed by the expansion of the wearer's thorax, from the positions shown schematically in FIG. 2 to those shown in FIG. 1. Should excessive pressure occur in the oxygen outlet supply chamber 13 for any reason, it is vented to the exterior by the safety valve 38.

For purposes of exemplification, a particular embodiment and modifications or the invention has been shown and described to the best understanding thereof. However, it will be apparent that minor changes and modifications in the arrangement and construction of the parts thereof may be resorted to without departure from the true spirit and scope of the invention as defined in the following claims.

I claim:

1. A high altitude full pressure suit comprising, an outer flexible nonextensible porous enclosure garment for a wearer, an inwardly spaced extensible and flexible liner within said outer porous nonextensible garment enclosure for enclosing a wearer in loose and comfortable relation at low altitudes where oxygen is not required, a plurality of closed expansible and contractable multicells disposed in said suit between said outer nonextensible garment and said inner extensible liner in close surrounding relation, around the wearer of the suit, said multicells having a predetermined amount of a gaseous medium trapped and sealed therein for expanding said multicells inwardly, according to Boyles Law upon predetermined reductions in exterior pressure surrounding the suit and said cells, away from said nonextensible outer garment and against said inner liner to move said inner liner inwardly into predetermined pressure supporting relation against the outer surface of the wearer, oxygen breathing means for supplying oxygen for inhalation and exhalation by the wearer, oxygen demand supply means connected to said oxygen breathing means for automatically supplying oxygen at predetermined pressures on demand to the wearer for breathing, means responsive to variations in the volume of the suit around the thorax area of the wearer during the wearers breathing cycle for varying the pressure of oxygen supplied by the demand regulator to the breathing means for the wearer to substantially balance the wearers lung pressure to the pressure of the multicells on the wearer's thorax area during the wearers breathing cycle.

2. A high altitude full pressure suit comprising, an outer, flexible, nonextensible, porous garment adapted to enclose the thorax area of a wearer therein, in predetermined spaced relation to the inner surface of said outer garment, a flexible, loose, and porous liner spaced within said outer garment enclosure for enclosing a wearer therein in comfortable ventilated relation at lower altitudes where a full pressure suit is not necessary, a plurality of closed, flexible, expandable and contractable multicells disposed in side-by-side closely spaced relation between said outer nonexpandable garment and said inner liner, said multicells each having a predetermined amount of gaseous medium trapped and sealed therein responsive to Boyles Law, upon reduction of exterior air presssures surrounding said suit and said cells for expanding said cells between said outer garment and said liner to force said liner inwardly into predetermined pressure supporting relation against the outer surface of a wearer of the suit at high altitudes where pressure on the outer surface of the body of a wearer of the suit is necessary, means for supplying breathing oxygen on demand to a wearer of the suit, including an oxygen demand supply regulator, a pressure responsive sensor disposed in the thorax area of the suit, responsive to variations in internal volume in the thorax area of the suit during the wearers breathing cycle for controlling the oxygen delivery pressure from said demand regulator to substantially balance the pressure of oxygen in the wearer's lungs to the pressure of the multicells on the surface of the thorax area of the wearer, during the wearer's breathing cycle.

3. A Boyles Law responsive, high altitude, full pressure, ventilated suit comprising an outer flexible, porous, nonextensible garment adapted to receive a wearer therein in predetermined inwardly spaced relation, a loose, flexible, porous, extensible liner spaced inwardly within said outer garment, adapted to enclose a wearer in loose confortable relation at lower altitudes where full pressure suits are not necessary, a plurality of closed flexible expandable and contractable multicells fixed in the suit between said outer garment and said liner in closely spaced side-by-side adjacent relation, said cells having a predetermined amount of a gaseous medium trapped and sealed therein, responsive to Boyles Law, upon reductions in exterior air pressure surrounding the suit and multicells, under conditions where a full pressure suit is required, to expand said multicells inwardly from said outer garment against said liner to force said liner inwardly into pressure supporting relation against the outer surface of a wearer of the suit at high altitudes where predetermined exterior supporting pressure on the body of a wearer is necessary, means responsive to volume changes in the thorax area of the suit for supplying breathing oxygen to the lungs of the wearer at predetermined pressures to balance the variations in multicell pressure on the wearers thorax area during the wearers breathing cycle.

4. An automatic high altitude ventilated full pressure suit comprising, an outer porous flexible nonexpansible garment for enclosing a wearers thorax area, an inwardly spaced expansible ventilated flexible liner loosely disposed within said outer garment for receiving a wearer therein, normally in loose and comfortable relation at low altitudes where a full pressure suit is not required, a plurality of closed expandable and contractable elongated multicells disposed in the suit between said outer garment and said liner in side-by-side closely spaced parallel relation to each other over the thorax area of the wearer, said cells having a predetermined amount of gas sealed therein responsive to Boyles Law, upon reductions in exterior pressure surrounding said cells for automatically expanding said cells from said outer garment inwardly for forcing said liner inwardly into pressure supporting relation against the thorax area of the body of the wearer upon predetermined exterior pressure reduction when a full pressure suit is required, variable demand pressure breathing means for supplying oxygen on demand to the wearer of the suit for balancing the inhalation and exhalation breathing cycle pressures in the lungs of the wearer to changes in cell pressure on the wearers thorax during his breathing cycle, of oxygen supplied by said pressure breathing means comprising, a pressure sensor responsive to volume changes in the thorax area of the suit during the wearers breathing cycle, for varying the pressure of the oxygen supplied to the wearer in predetermined relation to the changes in volume in the thorax area of the suit.

5. An automatic full pressure suit as defined in claim 4, in which said pressure sensor comprises a bellows in actuated contact with the thorax area of the wearer to be actuated thereby during the suit wearers breathing cycle by expansion and contraction of the wearer's thorax area, and means actuated by predetermined expansion and contraction of said bellows for controlling said oxygen pressure demand regulator for adjusting the oxygen pressure supplied to the wearer's lungs in predetermined balanced relation to the contraction and expansion of the cells in the thorax area of the suit.

6. An automatic full pressure suit and breathing means therefor comprising, an outer flexible, nonexpandable porous enclosure garment, an inner expansible, flexible liner disposed in inwardly spaced relation within said outer enclosure, a plurality of expansible and contractable flexible multicells fixed in closely spaced side-by-side relation between said garment and said liner, for surrounding the body of a wearer of the suit and covering the wearers thorax area, said cells each having a predetermined amount of gas sealed therein, expandable according to Boyles Law by reduction in the exterior air pressure surrounding said suit and cells to force said liner inwardly into pressure supporting relation on the body of a wearer upon pressure reductions when a full pressure suit is required, a pressure sensor fixed in the thorax area of the suit and adjustable by changes in volume in the thorax area of the suit due to the wearer's breathing cycle, an oxygen demand pressure regulator comprising means for supplying oxygen to the wearer on demand for breathing at predetermined pressures, and means operable by said pressure sensor for adjusting the pressure of oxygen supplied by said demand regulator to the wearer at pressures to substantially balance the pressure of said cells on the thorax area of the wearer during the wearer's inhalation and exhalation breathing cycles.

7. Apparatus as set forth in claim 6 in which said pressure sensor comprises a bellows for actuating contact with the thorax area of the wearer, compressed by expansion of the lungs and thorax area of the wearer, and expandable during a contraction of the wearer's lungs and thorax area, and operating means connected between said bellows and said oxygen demand regulator for automatically adjusting the pressure of oxygen supplied by said oxygen demand regulator, on demand by the wearer, to the lungs of the wearer at pressures to substantially balance the variations in pressure of said multicells on the wearer's thorax area, during the wearers breathing cycle.

8. An automatic full pressure suit responsive to Boyle's Law comprising, an outer flexible, nonexpandable, porous garment, a porous, extensible, flexible liner spaced inwardly substantially a predetermined distance from said outer garment, a plurality of expandable and contractable flexible multicells fixed in said suit in closely spaced relation to each other around the suit between the said outer garment and said liner and arranged to cover the thorax area of the wearer, said cells each having a predetermined amount of gas sealed therein and expandable, according to Boyle's Law, upon predetermined reductions in the exterior atmospheric pressure surrounding said garment and cells at altitude where a full pressure suit is required, causing the expansion of said cells to fill the space between the interior of said outer garment and said liner and force said liner inwardly into predetermined pressure supporting relation against the body and thorax area of the wearer of the suit, said suit having an oxygen supply helmet connected to the suit's neck portion, a gas seal between said suit and helmet to confine oxygen supplied to the helmet to the interior thereof for breathing by the wearer, said suit having multicells therein adapted to cover the thorax area of the wearer and expandable and contractable respectively during a wearers exhalation and inhalation breathing cycles, respectively increasing and decreasing the volume in the thorax area of the suit between the outer garment and the wearer responsive to exhalation and inhalation volume changes in the lungs of the wearer, an oxygen demand regulator connected for supplying oxygen on demand into said helmet at a predetermined normal pressure, an expansible and contractable pressure sensor fixedvin the thorax area of the suit responsive to changes in volume in the thorax area of the suit between the thorax area of the wearer and the outer garment during the suit wearers breathing cycle, operatively connected to said demand regulator for adjusting the oxygen pressure supplied from said demand regulator during the wearer's breathing cycle to substantially balance the oxygen pressure in said helmet and supplied thereby to the wearers lungs during the breathing cycle to variations in the multicell pressure on the wearers thorax area during the wearers breathing cycle.

9. Apparatus as set forth in claim 8, said pressure sensor comprising a closed expandable contractable pressure cell having a gaseous medium therein, bellows means in said demand regulator, expansible to increase the supply pressure of oxygen from said demand regulator and contractable to decrease the supply pressure of oxygen from said demand regulator to said helmet, a fluid supply conduit connected at one end in communication with the interior of said pressure sensor cell, and at its other end in communication with the interior of said bellows means in said pressure demand regulator.

10. A full pressure suit comprising an outer nonexpandable enclosure, pressure applying means in the suit responsive to predetermined reductions of the exterior air pressure surrounding said suit for automatically applying body supporting pressure to a wearer within the suit upon reduction in exterior pressure surrounding the suit under conditions when a full pressure suit is necessary, said suit including an oxygen supply helmet for enclosing the wearer's head and a neck seal for confining the supply of oxygen within the helmet for breathing by the wearer, an oxygen demand pressure regulator arranged for supplying oxygen on demand at a predetermined breathing pressure into said helmet, and breathing pressure sensor control means between the interior of the suit and the thorax area of a wearer thereof responsive to variations in volume between the interior of the suit and the thorax area of the wearer during the wearers inhalation and exhalation breathing cycles, including actuating means therefrom connected to said oxygen demand pressure regulator, actuated by said breathing pressure sensor control means for varying the oxygen pressure supplied to the wearers lungs from within said helmet, to always substantially balance the wearer's lung pressure during the breathing cycle to the body supporting pressure of said pressure applying means on the thorax area of the wearer. 

